Updates on the Silicon Tracker 2S Module 1,4 mm & 4,0mm versions

Previous CAD models used as a starting point

Previous 4,0mm module Previous 1,4mm module

Issues with previous models

Previous 1,4 mm module Sensors Difference in distance between hybrid board and sensors causes issues with wire bonding; difficult, poor reliability Hybrid Board Previous 4,0 mm module Hybrid Board Sensors

Main Changes

To bring sensors to equal distance from hybrid board, new contact pads are used

Upper sensor Hybrid Board ’S-shaped’ contact pads allow sensors to be distanced evenly relative to hybrid board Lower sensor Contact pad for 1,4mm module Contact pad for 4,0mm module

Other additions

A new layer of Kapton was added to insulate high voltage sensor surface from PGS, it extends over the edges of the sensors ¡High voltage surfaces!

A strip of Kapton tape underneath the contact pads helps minimize the distance needed between pads and sensors..

Modelling and materials

Modules with different distances between sensors share most components Main idea: Modules with different distances between sensors share most components 4,0mm Bridge Assmebly Main difference between 4,0mm and 1,4 mm version is the ’Bridge Assembly’ 1,4mm Bridge Assmebly

Possible changes to the ’Bridges Assembly’ If we use TPG for the bridge stiffener, do we need the PGS layer between stiffeners and sensors?

Main contributors to over all weight Item Weight in grams Sensors 9.02 Frame 7.74 Hybrid Boards 3.24 Optolink (on service board) 3.00 Contact Pads 2.21 DC-DC Converter (on service board) 2.07 PGS Layers 0.54 ASICs (on hybrid boards) 0.46 Connector 16-pin (on service board) 0.29 Screws 0.28 High Voltage related (Kaptons) 0.19 Main contributors to over all weight Complete module weight estimated to be 29,03 grams

Small changes possible to save weight / reduce material costs..

Two 2s Module types studied: 4,0mm module for end cap geometry, 1,4mm for barrel geometry Changes made to facilitate wire bonding Danger of discharges from high-voltage surfaces minimized Still to be resolved: Choice of materials for the Bridge Assembly i.e. just TPG or with PGS.. Need feedback from thermal and stuctural DEA study on this configuration Summary

We’ll start modelling a complete rod for the models, try positioning + cooling contact layouts First quotations from TPG suppliers received, waiting for samples.. Next